Coordinates detecting device, method for same and game device

ABSTRACT

The coordinates detecting device comprises a plurality of sensors (LS1, LS2: photosensors, or the like,) located in prescribed positions in a coordinates detecting region for detecting coordinates set on an image display surface (4) which displays images by means of scanning lines; a counter which counts the number of clock inputs with respect to the horizontal direction of the image display surface and the number of scans in the vertical direction, on the basis of the scan timing of the scanning lines as detected by the sensors; and a coordinates identifying circuit which, when a desired trigger signal (LP3) is input from an external source, outputs the count values of the counters at the time that this trigger signal is input as relative coordinates on the image display surface. The coordinates of any position can be determined accurately even when the display uses a special television format, such as HDTV, or the like, and regardless of differences in the scanning system.

TECHNICAL FIELD

The present invention relates to technology for detecting coordinates ata desired position on an image display screen (display), and moreparticularly to technology for identifying coordinates of, for example,the impact point of a gun fired at the display in a game device.

BACKGROUND ART

Technology for detecting coordinates at any point on a display exists inthe form of technology for identifying positions at which light isbeamed, and this technology is applied in the field of games devices,and the like. For example, in a game which involves shooting at gamecharacters represented on a display this technology is used to determinewhether or not a light ray emitted from a light ray gun has hit a gamecharacter, and it identifies the coordinates of the position at whichthe light ray hits the display surface.

Conventional coordinates detection of this kind makes use of thehorizontal synchronizing signal in the video signal generated by thegame device. In order to detect coordinates, the game device is providedwith a horizontal counter for counting the input number of each pictureelement in the video signal, a vertical counter for counting the numberof scanning lines, and a light ray gun for shooting at characters on thedisplay. The light ray gun is provided with a photosensor which receiveslight from light points on the scanning lines shown on the display, andwhich has a certain degree of directionality. In other words, the lightray gun does not emit a light ray, but rather it actually receives aportion of the light emitted from the display.

As the game program is progressing, the game device transmits videosignals to the monitor, whilst surveying whether or not a light ray hasbeen emitted from the light ray gun. If the game device determines thata light ray has been fired, the photosensor detects light emitted fromthe light point on the scanning line when the gun is fired and thisdetection signal is input to the game device. The game device reads thehorizontal counter and vertical counter when the detection signal isinput. The scanning position of the light point forming the scanningline is displaced in precise relationship with the synchronizingsignals, and therefore the values of each counter when the light pointis detected can be set as the coordinate values at the time the gun isfired.

However, when conventional coordinates detection technology has beenapplied to recent digitalized television devices, it has not beenpossible to detect coordinates accurately.

In television receivers based on new television formats, such as HDTV,the video signal is stored as digital data and undergoes prescribedsignal processing prior to image display. Therefore, a video signalsupplied from an external source is first stored in an internal memoryin the television receiver, and is then displayed as an image on areceiver tube at a timing which is independent of the synchronizationrelationship when the signal was supplied. Furthermore, even if a gameimage is displayed by converting the video signal output from a gamedevice to another image display system,-using a so-called videoconverter, or the like, there is frequent loss of synchronizationbetween the original video signal and the image shown on the display. Aslong as the timing at which images are shown on the display is notsynchronized with the video signal of the game device, the coordinatesobtained by counting the synchronizing signals in the video signal willnot match the actual position on the display at which the gun is fired.Moreover, in a standard television, images are displayed by interlacedscanning, but in some display devices, such as those used in personalcomputers, or the like, images are displayed by sequential scanning, andthis difference means that unless the coordinates detecting deviceidentifies whether the scanning method used in the display is interlacedscanning or sequential scanning, it is not possible to perform correctconversion of the coordinates.

DISCLOSURE OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide a coordinates detecting device capable of accurately detectingthe coordinates of any position on an image display surface, withoutdistinguishing between different image display systems, a method forsame, and a game device.

The coordinates detecting device of this invention comprises:

(a) a plurality of sensors (LS1, LS2; light-detecting elements, such asphotosensors) located at prescribed positions in a coordinates detectingregion for detecting coordinates set on an image display surface (4)which displays images by means of scanning lines;

(b) counters (209, 215) for counting the number of clock inputs withrespect to the horizontal direction of the image display surface andcounting the number of scans in the vertical direction, based on thescan timing of the scanning line detected by the sensors; and

(c) a coordinates determining circuit (213, 217: latch circuit, or thelike, latched by a trigger signal) which, when a desired trigger signal(LP3) is input from an external source, outputs the counter values atthe time that this trigger signal is input in the form of relativecoordinates on the image display surface.

The coordinates detecting device of this invention comprises:

(a) an initial position detecting sensor (LS1) for detecting the scantiming of scanning lines, which is located at the initial scanningposition in a coordinates detecting region for detecting coordinates seton an image display surface (4) which displays images by means ofscanning lines (for example, the top left corner of the display or thetop left corner of a subframe which depicts a separate image in aportion of the display);

(b) a horizontal direction counter (209) for counting the number ofinputs of a prescribed clock;

(c) a scanning cycle determining circuit (210: latch circuit, or thelike) for initiating a counting operation of the horizontal directioncounter when a scan timing of the scanning lines is initially detectedby the initial position detecting sensor (LS1), and setting the valuecounted by the horizontal direction counter (209) until the scan timingof the next scanning line is detected by the initial position detectingsensor (LS1) as the scanning cycle count value;

(d) a reset circuit for resetting the count value of the horizontaldirection counter (209) each time this count value reaches the scanningcycle count value (211: generates a reset signal when the counter valuematches the horizontal limit count in a coincidence circuit); and

(e) a horizontal coordinate determining circuit (213: latch circuit, orthe like, latched by a trigger signal) which, when a desired triggersignal (LP3) is input from an external source, takes the count value ofthe horizontal direction counter at the time that this trigger signal isinput and sets it as a relative coordinate in the horizontal directionfrom the initial scanning position on the image display surface.

The coordinates detecting device of this invention comprises:

(a) a final position detecting sensor (LS2) for detecting the scantiming of scanning lines, which is located at a desired final scanningposition on the image display surface (4) (for example, the bottom rightcorner of the image display surface or subframe);

(b) a vertical direction counter (215) for counting the number of timesthat the count value of the horizontal direction counter (209) reachesthe scanning cycle count value;

(c) a horizontal limit determining circuit (213: latch circuit, or thelike) for setting the count value of the horizontal direction counter(209) when a scan timing of the scanning lines is detected by the finalposition detecting sensor (LS2) as a horizontal limit value:

(d) a vertical limit determining circuit (216: latch circuit, or thelike) for setting the count value of the vertical direction counter(215) when a scan timing of the scanning line is detected by the finalposition detecting sensor (LS2) as a horizontal limit value; and

(e) a vertical coordinate determining circuit (217: latch circuit, orthe like, latched by a trigger signal) which, when a desired triggersignal (LP3) is input from an external source, takes the count value ofthe vertical direction counter (215) at the time that this triggersignal is input and sets it as a relative coordinate in the verticaldirection from the initial scanning position on the image displaysurface (4).

The coordinates detecting device of this invention compriseslight-detecting means (LS3: photosensor, or the like) for receivinglight emitted from a desired position (PO) on the image display surface,detecting the scan timing of the scanning lines, and outputting adetection signal relating to the detected scan timing in the form of atrigger signal (LP3).

The game device of this invention comprises a coordinates detectingdevice of this invention, the light-detecting means being provided in ashooting device for shooting at targets in a game program represented onthe image display surface.

The coordinates detecting device of this invention comprises:

(a) light-detecting means (6: photoelectric converter elements, such assolar cells, photosensors, or the like) for detecting light (L) beamedfrom an external source onto a desired position on an image displaysurface (4) for displaying images by means of scanning lines, andoutputting detection signals (DV, DH) corresponding to this beamed light(L), which is transparent to light and is positioned such that it coversthe image display surface (4); and

(b) coordinates identifying means (301˜304, 401, 402) for detecting theposition at which the beamed light is beamed onto the light-detectingmeans (6) on the basis of the detection signals (DV DH) supplied by thelight-detecting means (6), and outputting the detected position asrelative coordinates on the image display surface (4).

The coordinates detecting device of this invention is composed such that

the light-detecting means (6) comprises light-detecting elements fordetecting light beamed onto divisions of a prescribed size, arranged inthe shape of a matrix (M rows×N columns); and

the coordinates identifying means (2b, 2c) comprises: (a) a horizontalcoordinate identifying section (302, 304, 402: shift register,multiplexer, and the like) for identifying the column containing thelight-detecting element where the beamed light is detected, from aplurality of columns each constituted by a collection (Pn1₋₋ PnM:1≦n ≦N)of light- detecting elements aligned extending in the vertical directionof the image display surface (4); and (b) a vertical coordinateidentifying section (301, 303, 401: shift register, multiplexer, and thelike) for identifying the row containing the light-detecting elementwhere the beamed light is detected, from a plurality of rows eachconstituted by a collection (P1m₋₋ PNm:1≦m≦M) of light-detectingelements aligned extending in the horizontal direction of the imagedisplay surface (4).

The coordinates detecting device of this invention is composed such thatthe coordinates-identifying means (2b, 2c) comprises a filter (404) forremoving frequency components corresponding to the image display cyclefrom the detection signals supplied by the light-detecting means (6).

The coordinates detecting device of this invention is composed such that

the coordinates identifying means (2b, 2c) comprises a filter (405) forremoving commercial power supply frequency components from the detectionsignals supplied by the light-detecting means (6). For the filter inclaim 8 and claim 9, a low-band filter providing sufficient attenuationof frequency components corresponding to the image display cycle (5.0 Hzor 15 kHz, or the like) and the commercial power supply frequencycomponent (50 Hz or 60 Hz, or the like), or a notch filter whichprovides excellent attenuation of these frequency components, may beapplied.

The game device of this invention comprises a coordinates detectingdevice of this invention, and it comprises a shooting device foremitting a beam of light when shooting at targets in a game programrepresented on the image display surface,

The coordinates detecting method of this invention comprises the stepsof:

(a) arranging a plurality of sensors for detecting the scan timing ofscanning lines in a coordinates detecting region for detectingcoordinates set on an image display surface for displaying images bymeans of scanning lines;

(b) starting a horizontal direction count for counting the number ofinputs of a prescribed clock from the time that a scanning line isinitially detected by a sensor located at an initial scanning positionin the coordinates detecting region;

(c) setting the value counted by the horizontal direction count up tothe time that the next scanning line is detected as the scanning cyclecount value;

(d) resetting this count value and reinitiating a count in thehorizontal direction each time the count value reaches the scanningcycle count value, and simultaneously conducting a count in the verticaldirection to count the number of times this count value reaches thescanning cycle count value;

(e) setting the count values according to the count of clock inputs forthe horizontal direction and the count for the vertical direction,respectively, as a horizontal limit value and a vertical limit value,when the scanning lines are detected by a sensor located at a finalscanning position in the image detection region; and

(f) when a desired trigger signal is input from an external source,outputting the count value according to the count in the horizontaldirection and the count value according to the count in the verticaldirection at the time that this trigger signal is input as relativecoordinate values on the image display surface.

According to This invention, sensors detect the timing at which thelight point of the scanning line passes through prescribed positions ina coordinates detecting region for detecting coordinates (for example,the point where the scanning line initially starts scanning in theregion, the point where a second scanning line starts, and the finalscanning point in this region). If counters perform a count in thehorizontal direction and a count in the vertical direction from thedetected timings, the count values of each counter will indicate therelative coordinates from the point at which the count was started.

Therefore, if a trigger signal from an external source indicates thatthe light point of a scanning line on this image display surface hasbeen detected, then the count values of the counters at the time thatthis trigger signal is input will form relative coordinates for theposition where the light point has been detected from the point wherethe count was started.

According to this invention, initial position detecting sensors detectthe light point of a scanning line passing through both the point wherethe light point starts scanning of the first scanning line, and thepoint where it starts scanning of the next scanning line (in otherwords, transit points of adjacent scanning lines), in the coordinatesdetecting region. Since the horizontal direction counter counts aprescribed clock from the time that the light point passes initiallyuntil the time that it next passes, the scanning cycle count valuedetermined by the scanning cycle determining circuit is a count valuecorresponding to the scanning cycle of the scanning line. Furthermore,since the reset circuit resets the horizontal direction counter eachtime the scanning cycle count value is counted, the count value of thehorizontal direction counter indicates a relative coordinate in thehorizontal direction from the initial scanning position.

Therefore, if a trigger from an external source indicates that the lightpoint of the scanning line on this image display surface has beendetected at a desired position, then the count value of the horizontaldirection counter at the time when this trigger signal is input willindicate the relative coordinate in the horizontal direction from theinitial scanning position of the position where the light point wasdetected.

According to this invention, since the vertical direction counter countsthe number of times the count value of the horizontal direction counterreaches the scanning cycle count value (corresponding to scanning cycle)(count-up, or the like), the count value of the vertical counterindicates the relative coordinate in the vertical direction from theinitial scanning position (scanning line number, or the like). If thetrigger signal from an external source indicates that the light point ofthe scanning line on this image dismay surface has been detected at adesired position, then the count value for the vertical directioncounter at the time that this trigger signal is input will indicate therelative coordinate in the vertical direction from the initial scanningposition of the position at which the light point was detected. Sincethe final position detection sensor is located at the final positionthat the scanning line passes through in the coordinates detectingregion, the values of the horizontal direction counter and the verticaldirection counter at the time that the light point of the scanning linepasses through this position will indicate the relative coordinates ofthe final point in the coordinates detecting region.

According to this invention, since the light emitted from the imagedisplay surface is detected by-light-detecting means, a trigger signalis output when the light point of a scanning line passes through adesired point on the image display surface.

According to this invention, the light-detecting means outputs theemitted light directly as a detection signal, and the coordinatesidentifying means converts the position at which the light is incidentto coordinate values.

According to this invention, since the light-detecting means isconstituted by light-detecting elements arranged in a matrix, theposition within the matrix of the light-detecting element at which thelight is incident is used to give coordinate values.

According to this invention, since the filter removes frequencycomponents corresponding to the image display cycle from the detectionsignal (for example, in an NTSC image display system, verticalsynchronizing frequency 50 Hz or horizontal synchronizing frequency15.75 kHz), then even if light from the scanning line displaying theimage enters into the light-detecting means, only the frequencycomponents corresponding to the beamed light will be extracted.

According to this invention, since the filter removes commercial powersupply frequency components from the detection signal (for example, 50Hz or 60 Hz), then frequency components entering into thelight-detecting means from fluorescent or incandescent lights areremoved, and only the frequency component corresponding to the beamedlight is extracted.

According to this invention, when shooting at a target displayed in agame program, the point of impact is detected accurately by implementingcoordinates detection according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a general compositional view of a game device comprising acoordinates detecting device in a first mode for implementing thepresent invention;

FIG. 2 is a diagram showing an example of the layout of sensors on adisplay surface in a first mode for implementing the present invention;

FIG. 3 is a circuit diagram from the sensors up to the control circuitinput stage;

FIG. 4 is a circuit diagram of a control circuit;

FIG. 5 is a timing chart describing the operation of a control circuit;

FIG. 6 is a timing chart describing the operation of a coordinatesdetecting device in a first mode for implementing the present invention;

FIG. 7 is a general compositional view of a game device comprising acoordinates detecting device according to a second mode for implementingthe present invention;

FIG. 8 is a compositional view of a control circuit (coordinatesidentifying means) according to a second mode for implementing thepresent invention; and

FIG. 9 is a compositional view of a control circuit (coordinatesidentifying means) according to a third mode for implementing thepresent invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Below, modes for implementing the present invention are described withreference to the appropriate drawings.

(I) First mode

In the first mode for implementing the present invention, a coordinatesdetecting device according to the present invention is applied in a gamedevice, and coordinates are detected by providing sensors on a displayforming an image display surface.

(Description of the Composition)

FIG. 1 shows the general composition of the first mode for implementingthe present invention. As shown in FIG. 1, the coordinates detectingdevice according to the present mode comprises a game main unit 1a whichcontrols a game, a monitor 4 for displaying images based on a videosignal V output from the game main unit 1a, a control circuit 2awhichoperates as a coordinates detecting device according to the presentinvention, and a light ray gun 3a which is used by a player during thegame to "shoot" at characters.

The game main unit 1a generates virtual images for the gamecorresponding to the development of the game (hereinafter, called "gameimages"), in accordance with a game program stored in an internal ROM,or the like (omitted from drawings). The generated game images aremodulated to a prescribed television format (for example, NTSC format,)and are supplied to the monitor 4 as a video signal V.

The monitor 4 is provided with a display surface D which forms the imagedisplay surface of the present invention. The monitor 4 inputs the videosignal V modulated to the aforementioned television format and convertsit to digital data, whereupon the image is displayed using a differentimage display system to the input video signal (for example, an HDTVsystem). Sensors LS1 and LS2, which form sensors for position detectionaccording to the present invention, are attached to the display surfaceD using suckers or some other method of attachment.

Each sensor is constituted by a light-detecting element such asphotosensor, or the like, and at the instant that the light point of ascanning line passes through the point at which a sensor is attached, adetection signal is output. The detection signal LP1 from sensor LS1 andthe detection signal LP2 from sensor LS2 are input to the controlcircuit 2a. A sensor LS3 which supplies the external trigger signalaccording to the present invention is provided on the light ray gun 3ain the region of the barrel thereof. By combination with lenses omittedfrom the drawings, this sensor LS3 has a very precise directionalitywhereby it only receives light emitted from one point on the displaysurface D corresponding to the aim of the light ray gun 3a. When theuser operates the trigger T, the sensor LS3 receives light from thedisplay D for a period of time longer than the standard image displayperiod (one frame or one field), and it outputs a detection signal LP3.The light ray gun 3a supplies this detection signal LP3 to the controlcircuit 2a. The control circuit 2a identifies the position PO of thelight point of the scanning line detected by the sensor LS3 in the lightray gun 3a, and outputs it as a coordinates signal SXY to the game mainunit 1a. Based on this coordinates signal SXY, the game main unit 1adevelops the game further in accordance with whether or not the player'sshot was successful.

FIG. 2 shows an example of the layout of sensors on the display surface.When the game involves displaying game images across the entire display,the sensor LS1 forming a start position sensor is located, for example,at position P1 at the top left corner of the display, which is theinitial scanning position of the scanning line. In this case, the sensorLS1 is located in a position covering at least two scanning lines suchthat as well as detecting the scanning line /1 which appears initiallyon the display surface, the sensor LS1 can also detect scanning of theadjacent scanning line /2 which scans after this scanning line /1 (thecentre of the sensor is in a position corresponding to the centre pointbetween two scanning lines /1 and /2). The sensor LS1 is of sufficientsize to cover the two scanning lines /1 and /2, and it detects thepassage of the light point of a scanning line at least two times, andoutputs at least two detection signals, at an interval equal to thehorizontal synchronization period. The sensor LS2 forming a finalposition sensor is located, for example, at position P2 on the bottomright of the display, which is the final scanning position of the lastscanning line /n. If the player pulls the trigger of the light ray gun3a, for example, then at the instant that the light point of thescanning line passes through the aim point PO of the light ray gun 3a,the sensor LS3 detects the light emitted from this point PO and adetection signal LP3 is output.

Since the monitor 4 is provided with a function whereby a subframecontaining a further image can be shown in a portion of the display,when the player causes game images to be displayed in the subframewhilst playing the game, then of the four corners of the subframe,sensors are, for example, positioned at the top left and bottom rightcorners thereof. For instance, with respect to subframe DC in FIG. 2,sensor LS1 is located at position P1' such that it covers scanning lines/C1 and /C2, and sensor LS2 is located at position P2' such that itcovers scanning line /Cn.

Even if the monitor 4 uses a television format involving interlacedscanning, there is no change to the coordinates detection operation.Specifically, in the case of interlaced scanning, between theodd-numbered fields and the even-numbered fields, there is divergence inthe scanning position of the scanning lines of approximately half thescanning line pitch, but this divergence is only slight and the sensorswill be able to detect scanning lines by conducting coordinatesdetection in any of the fields.

FIG. 3 shows a circuit diagram from each sensor up to the input stage ofthe control circuit 2a. Sensors LS1₋₋ LS3 are constituted byphotoelectric converter elements, such as phototransistors, or the like.When light is incident, the phototransistor cuts off and the outputlogic state changes. Inverters 111₋₋ 113 function as output buffers forthe phototransistors. Elements other than phototransistors may be usedfor the sensors, provided that their output voltage or resistance valuechanges with the strength of received light.

At the input stage of the control circuit 2a, flip-flops 101₋₋ 106convert the detection signals from-each sensor to signals synchronizedto a CLK generated by a clock circuit 107. For example, the output LP1'from sensor LS1 becomes detection signal LP1 by means of timing controlaccording to the timing chart shown in FIG. 5 effected by flip-flops 101and 104. The detection signal LP1 is synchronized to the rise of theclock CLK, and it has a cycle equal to that of the clock CLK. LP2' andLP3' are similarly converted to detection signals LP2 and LP3.

The clock CLK generated by the clock circuit 107 determines theresolution in the horizontal direction of the coordinates detectingcircuit. Therefore, the frequency of the clock CLK is set to a frequencywhereby satisfactory resolution can be obtained, whatever the televisionformat. For example, firstly, the maximum coordinate number in thehorizontal direction, namely, the horizontal resolution in coordinatesdetection, is determined. The predetermined maximum coordinate is numbermultiplied by the horizontal synchronizing frequency of the televisionformat having the highest horizontal synchronizing frequency of thetelevision formats to which coordinates detection may be applied. Thismultiplied value is set as the oscillating frequency of the clock CLK.

FIG. 4 shows the second stage of the control circuit 2a. The inverters201₋₋ 203 invert the signal logic of each detection signal LP1₋₋ LP3.The flip-flops 204, 206, inverter 205 and gate 207 output a signal atlevel L for the period of the scanning cycle (namely, the horizontalscanning cycle), on the basis of the detection signal generated by meansof sensor LS1 detecting scanning of the first scanning line after thevertical retrace ratio, and the detection signal generated by sensor LS1detecting scanning of the next scanning line. Horizontal directioncounter 209 comprises, for example, a counter equipped with a loadfunction for counting up a clock CLK, and it performs a countcorresponding to the horizontal coordinate value. The scanning cycledetermining circuit 210 comprises a latch circuit, for example, whichlatches the output of the horizontal direction counter 209, therebylatching the count value during the scanning cycle. The reset circuit211 comprises a coincidence circuit, for example, which compares thecount value for the scanning cycle latched by the scanning cycledetermining circuit 210 with the count value of the horizontal directioncounter 209, and sets the output E to level L if the two count valuesagree. The horizontal limit circuit 212 and vertical limit circuit 216comprise latch circuits, for example, which latch the count value of thehorizontal direction counter 209 at the rise of the detection signalLP2. The horizontal coordinate determining circuit 213 and the verticalcoordinate determining circuit 217 comprise latch circuits, for example,which latch the count value of the horizontal direction counter 209 whenthe detection signal LP3 corresponding to the trigger signal from thelight ray gun 3a is input. The count value latched by the horizontallimit circuit 212 forms the horizontal limit value HLIMIT, and the countvalue latched by the vertical limit circuit 216 forms the vertical limitvalue VLIMIT. Furthermore, the count value latched by the horizontalcoordinate determining circuit 213 forms the horizontal coordinate HPOS,and the count value latched by the vertical coordinate determiningcircuit 217 forms the vertical coordinate VPOS.

Different circuits may be used for each of the aforementionedconstituent elements, provided that they perform the same functions andoperations as those described above. Furthermore, in the circuits shownin FIG. 4, the count values are four bits long, but the bit length maybe increased freely depending on the accuracy required in the gamedevice.

(Description of the Operation)

Next, the operation of the first mode for implementing the presentinvention is described with reference to the timing chart in FIG. 6.

When the image display period is completed, the monitor scans the finalscanning line/h (see FIG. 2). The sensor LS2 detects light when thelight of the electron beam passes through the final scanning positionP1, and it outputs a detection signal LP2'. The timing of this detectionsignal LP2' is modulated at the input stage of the control circuit 2a,and it is then input to the second stage of the control circuit 2a (seeFIG. 4). The detection signal LP2 always clears the flip-flops 204 and206 (sets output Q to "0"), and sets point A and point B in FIG. 4 tolevel L.

When the light point having scanned one image display period isretraced, the monitor 4 starts again to scan the scanning line /1 fromthe initial scanning position P1 on the display D. Sensor LS1 detectsthe light point passing through it and inputs the detection signal LP1to flip-flop 204. Consequently, point A changes to level H, whilst pointB is maintained as level L. When scanning line /2 is scanned followingscanning line /1, the sensor LS1 again detects the light point passingthrough it and again it inputs LP1. In this case, point A is maintainedat level H and point B is changed to level H.

Meanwhile, the-detection signal LP1 relating to scanning line /1 issupplied via the AND gate 208 to the horizontal direction counter 209 asa load pulse. The horizontal direction counter 209 loads the count value"0", and therefore after the load pulse has reverted to level H, itstarts a count of the clock CLK. This count value C is supplied to thedata input terminal of the scanning cycle determining circuit 210.Furthermore, in response to the changes at point A and point B, the ORgate 207 supplies a pulse to the clock terminal of the scanning cycledetermining circuit 210 which takes level L only for the horizontalsynchronizing period between scanning lines /1 and /2. The count valuelatched when this pulse rises, in other words, when the count for thehorizontal synchronizing period is completed, is the value countedduring the scanning cycle. Since the scanning lines each have the samescanning cycle, the latched count value D ("5" in FIG. 6) takes a valuecorresponding to the scanning cycle of this image display format(horizontal synchronizing period). For example, if the oscillatingfrequency of the clock CLK is set to a value obtained by multiplying thehorizontal synchronizing frequency of the NTSC format by the resolutionN, then the count value latched by the scanning cycle determiningcircuit 210 will be N.

The reset circuit 211 inputs the count value D latched by the scanningcycle determining circuit 210 to one comparative input terminal, and itinputs the count value C from the horizontal direction counter 209 to another comparative input terminal. The count value D corresponding to thehorizontal synchronizing period and the count value C from thehorizontal direction counter 209 are compared, and if they match, inother words, if the count has reached a count value corresponding to thehorizontal synchronizing period, then the reset circuit 211 output areset signal E. This reset signal E resets the horizontal directioncounter 209 via the AND gate 208, and therefore the horizontal directioncounter 209 repeats a similar count from the start of each scanningline.

Meanwhile, the pulse supplied via the OR gate 207 forms a load pulse forthe vertical direction counter 215, and therefore, from scanning line/2, where the output of the OR gate 207 is set to level H, the verticaldirection counter 215 counts load pulses for the horizontal directioncounter 209 input via the AND gate 208. A load pulse is output from theAND gate 205 by means of the detection signal LP1 during scanning ofscanning lines /1 and /2, and by means of the reset signal E generatedby the reset circuit 211 during scanning of the subsequent scanninglines, Therefore, even when the detection signal LP1 ceases to be input,the counting operation of the vertical direction counter 215 willcontinue each time scanning of a scanning line is completed.

It is now supposed that a player pulls the trigger of the light ray gun3a and shoots at a character depicted on the display, whilst the imageis being scanned. A time period equal to least one image display period(field period or frame period) is required for the light point to bedetected when the trigger is pulled. If the players shoots at the topleft of the screen, the trigger with be detected at the start of theimage display period, whilst if the player shoots at the bottom right ofthe screen, the trigger will be detected at the end of the image displayperiod. During the period for detecting the light point, the light raygun 3a outputs a detection signal LP3' at the instant that the lightpoint passes through the position on the display at which the gun isaimed. For example, in FIG. 2, the gun is aimed at position PO, so thedetection signal LP3' is output at the instant that the light pointpasses through position PO on scanning line In. The timing of thedetection signal LP3' is modulated at the input stage of the controlcircuit 2a, whereupon it input to the control circuit 2a as a detectionsignal LP3 and supplied to the horizontal coordinate determining circuit213 and the vertical coordinate determining circuit 217. Count value Cfrom the horizontal direction counter 209 and count value G from thevertical direction counter 215 are supplied respectively to thesedetermining circuits, which accordingly latch the respective countvalues at the rise of the detection signal LP3. Since the horizontalcoordinate determining circuit 213 latches the horizontal count value Cfrom the initial scanning point of the scanning line, this latched countvalue forms a coordinate value corresponding to the position at whichthe light ray gun 3a is aimed. Since the vertical coordinate determiningcircuit 217 latches the vertical count value from scanning line /2, inother words, the scanning line value, this latched count value forms arelative value corresponding to the position at which the light ray gun3a is aimed. The divergence between two scanning lines is so slightcompared to the dimensions of the display as a whole that it can beignored in practical use. The values latched by the coordinatedetermining circuits indicate the coordinate values (HPOS, VPOS) for thepoint of aim of the gun when the top left corner of the display D istaken as the origin (0,0) and the coordinates are set at a prescribedresolution. In order to achieve accurate values for the verticalcoordinate, the game main unit 1 a should add "2" to the vertical countvalue D, to convert the vertical coordinate to VPOS=D+2.

As scanning continues, the instant that the light point passes throughthe final scanning position P2 on the last scanning line /n, the sensorLS2 outputs a detection signal LP2'. This detection signal LP2' passesthrough the input stage of the control circuit 2a and is supplied to thesecond stage of the control circuit 2a as a detection signal LP2. Thisdetection signal LP2 clears the flip-flops 204, 206, as described at thebeginning of this description of the operation, and also forms a latchsignal for the horizontal limit circuit 212 and the vertical limitcircuit 216. The horizontal count value C and the vertical count value Gare supplied respectively to the data input terminals of the limitcircuits. Thereby, the count values latched at the instant thatdetection signal LP2 rises form the bottom right coordinates (HLIMIT,VLIMIT) of the display D.

The identified coordinates (HOPS, VPOS) and the limit coordinates(HLIMIT, VLIMIT) output from the control circuit 2a are supplied to thegame device 1a. The game device 1a can determine the size of the displayfrom the limit coordinates and it can determine the relative point ofaim of the gun from the identified coordinates. The coordinates dataprocessing is conducted in accordance with the game program in the gamedevice.

If a game, or the like, is played in a subframe DC as shown in FIG. 2,then the sensors LS1 and LS2 will be located respectively at positionsP1' and P2' in FIG. 2. The basic operation is similar to that describedabove. If the player shoots at any point of the subframe DC using thelight ray gun 3a, the identified coordinates (HPOS, VPOS) latched by thehorizontal coordinate determining circuit 213 and the verticalcoordinate determining circuit 217 form relative coordinates for thepoint at which the gun is aimed, taking point P1' as the origin.Moreover, if the gun is fired at a region outside the subframe DC, theremay be cases where the identified coordinates (HPOS, VPOS) exceed thevalues of the limit coordinates (HLIMIT, VLIMIT) latched by thehorizontal limit circuit 212 and the vertical limit circuit 216. In thiscase, the game device 1a should treat the identified coordinates asinvalid.

(Merits of the Present Mode)

The principal merits of the first mode for implementing the presentinvention are given below.

i) Since a sensor for detecting scanning of a plurality of scanninglines is located at the position where scanning starts in the regionwherein coordinates are to be detected, a circuit is provided which iscapable of detecting the horizontal coordinate and the verticalcoordinate of a position at which a light ray gun is fired.

ii) Since the scanning of a scanning line is detected at the positionwhere scanning is completed in the region wherein coordinates are to bedetected, it is possible to use the counter values reached when scanningis detected at this position as limit values indicating the size of thecoordinates detection region.

iii) The count values latched by the coordinates determining circuitscan be used directly as coordinate values.

(II) Second mode

The second mode for implementing the present invention differs from thefirst mode for implementing the present invention, wherein sensors areprovided on a display, in that transparent sensors capable of detectingcoordinates are provided on the front surface of the display.

(Description of the Composition)

FIG. 7 shows the general composition of a second mode for implementingthe present invention. As shown in this diagram, the coordinatesdetecting device according to this mode comprises: a game main unit 1bwhich controls a game; a monitor 4 for displaying images based on avideo signal V output from the game main unit 1b; a light sensor panel5, attached to the front surface of the monitor 4, for receiving lightemitted from a light ray gun 3b; a control circuit 2b which operates asthe coordinates detecting device according to the present invention; anda light ray gun 3b which is used by a player during the game to "shoot"at characters.

The light ray gun 3b differs from the light ray gun 3a in the firstmode, which was provided with a photosensor, in that it is equipped witha light-emitting diode 6 which emits light, When the player pulls thetrigger T, the light-emitting diode 6 emits light for a time periodsufficiently longer than the standard image display time period (1 fieldor 1 frame), and a signal ST indicating that the trigger T has beenoperated is output to the game main unit 1b. Preferably, this period issufficiently longer than the commercial power oscillating frequency andthe image display vertical synchronizing period and horizontalsynchronizing period. Furthermore, the element emitting light shouldhave precise directionality, such that light can be beamed onto aparticular region of the image display surface, and it should emit lighthaving suitable characteristics for detection by the light sensor panel5.

The game main unit 1b has the same composition as that in the firstmode, but it differs from the first mode in that it is programmed suchthat the coordinates signal SXY supplied from the control circuit 2b isread out when a signal ST indicating that the trigger has been operatedis supplied from the light ray gun 3b. The monitor 4 has the samecomposition as that in the first mode.

FIG. 8 shows the composition of a light sensor panel 5 corresponding tothe light-detecting means of the present invention, and a controlcircuit 2b corresponding to the coordinates identifying means. The lightsensor panel 5 comprises light-detecting elements arranged in the shapeof a matrix. Each light-detecting element should be such that onreceiving light emitted from the light ray gun 3b it outputs a detectionsignal corresponding to the strength of the received light. For example,as shown in FIG. 8, it may comprise solar cells Pc, or phototransistorsPt, arranged in each section of the matrix. Any other photoelectricconverter element based, for example, on a photovoltaic effect wherebyan electromotive force is produced when light is received, or aphotoconductive effect whereby the resistance changes when light isreceived, may be used, provided that there is no risk of interferingwith the image on the display (the element must be transparent and havea small area). If solar cells are used for the light-detecting elements,preferably, they should be formed by vaporization of amorphous siliconin an extremely thin layer which is shaped to produce a transparentfilm. This is because if it is transparent, it will not interfere withthe image on the display. Each cell is provided with diodes to preventreverse currents for the row output and column output, respectively.Each light-detecting element outputs a voltage to the matrix row m(1≦m≦M) and column to which it belongs. For each row, a detection signalconnecting the outputs from each light-detecting element in that row issupplied to the control circuit 2b as a vertical direction detectionsignal DV, and for each column, a detection signal connecting theoutputs from each light-detecting element in that column is supplied tothe control circuit 2b as a horizontal direction detection signal DH.

The control device 2b comprises amplifying circuits, latch circuits andshift registers. The amplifying circuits 301, 302 provide an amplifyingfunction by means of an operational amplifier, for example, which isparticularly necessary when solar cells Pc are used as thelight-detecting elements, The output voltage of each solar cell is a lowvoltage of about 0.5 V, and since this cannot be output directly to adigital circuit, the amplifying circuits amplify this output voltage toa level suitable for use as level H in a digital signal. In theoperational amplifiers, the rate of amplification may be set byresistances R1, R2, and the cut-off frequency, by capacitor C and R1, asshown in the diagram. The cut-off frequency is set to a frequencywhereby the commercial power frequency (50 Hz or 60 Hz, or the like,)and the image display frequency of the display (in NTSC format, verticalsynchronizing frequency of 50 Hz and horizontal synchronizing frequencyof 15.75 kHz) are sufficiently attenuated. Since the light sensor panel5 also receives light from sources other than the light ray gun 3b, suchas the display and fluorescent lamps or other lighting means in theroom, it is necessary for the frequency components of light from thesesources other than the light ray gun 3b to be attenuated.

Latch circuits 303, 304 latch the amplified detection signals DV or DH.The latch timing is generated by a wired OR circuit 307. A wired ORcircuit 307 outputs a level H signal when a level H output voltageappears in any of the signal lines for the detection signals. A buffer309 supplies this level H signal to each of the latch circuits, andtherefore, whenever a change is detected in the level of a detectionsignal, the logic state of each detection signal is latched. Whenphototransistors are used for the light-detecting elements, amplifyingcircuits are not required. However, if amplifying circuits are provided,then the signal logic is inverted, so inverters, or the like, will benecessary. Furthermore, switch circuits based on transistors, or thelike, may be used in place of the amplifying circuits based onoperational amplifiers. In this case, since the output voltage from thesolar cells will be too low to change the transistors or other switchesto an ON state, a reference voltage which enables the switch circuits tobe operated may be supplied to the negative terminal of each solar cell.

Shift register circuits 305, 306 perform a parallel-to-serial conversionof the logic states of the detection signals latched by latch circuit303 or 304. A transmitter 310 transmits serial data transferred from theshift register circuits 305, 306 to the game main unit 1b. A clockcircuit 308 receives latch signals from the wired OR circuit 307 andgenerates load signals for loading data to the shift register circuits305, 306 and a shift clock for the shift operation.

(Description of the Operation)

Next, the operation of the second mode is described.

When light is emitted from the light ray gun 3b, the light falls on thelight-detecting element on the light sensor panel 5 which corresponds tothe aim of the gun when the light was emitted. The light-detectingelement on which the light falls changes its output voltage. As aresult, the bits corresponding to all the signal lines for the verticaldirection detection signal DV and all the signal lines for thehorizontal direction detection signal DH are latched to the latchcircuits 303, 304 at level H. The data latched to latch circuit 303gives a coordinate in the vertical direction and the data latched tolatch circuit 304 gives a coordinate in the horizontal direction. Thesebit states are output directly to the game main unit 1b by the shiftregister circuits 305, 306. The game main unit 1b is able to obtaincoordinates by reading the serial data supplied to it.

The principal merits of the second mode are given below.

i) Since the light sensor panel forming the light-detecting meanscorresponds to the absolute coordinates on the display forming the imagedisplay surface, the light emitted from the light ray gun can beconverted directly and accurately to coordinate values.

ii) If a transparent amorphous solar cell film is used for thelight-detecting elements, coordinates can be detected withoutinterfering with the image on the display.

iii) Since the light ray gun is simply required to emit light for aprescribed period of time, the manufacture and design of the light raygun forming the light emitting means are simplified.

iv) If the amplifying circuits comprise filters, then it is possiblereadily to exclude light from sources other than the light ray gun.

(III) Third mode

The third mode for implementing the present invention shows a differentmode for implementing the control circuit in the second mode.

(Description of the Composition)

FIG. 9 shows the composition of a control circuit 2c in this third mode.Since the constituent elements other than the control circuit are of thesame composition as the second mode described above (see FIG. 7),description thereof is omitted here.

A multiplexer 401 selects each column in sequence from the verticaldirection detection signal DV in accordance with a selection signal SAoutput from the clock circuit 409. A multiplexer 402 selects each row insequence from the horizontal direction detection signal DH in accordancewith the selection signal SA. Both multiplexers supply output signals insequence to an amplifying circuit 403. The amplifying circuit 403amplifies the output signal up to a prescribed voltage level. A filter404 and a filter 405 are low-band filters provided with a cut-offfrequency and attenuation characteristics whereby, respectively, thelevel of commercial power frequency components and the level of verticalsynchronizing frequency components can be sufficiently reduced. Afiltering function may be provided in the amplifying circuit itself, asin the amplifying circuits 301, 302 in the second mode, instead ofproviding the filters 404 and 405. A comparator 406 compares the outputsignal with a prescribed reference potential. A buffer 407 transmits theoutput signal after wave-shaping, and a buffer 408 transmits a clockSCLK, respectively, to the game main unit 1b. A clock circuit 409outputs to the multiplexers 401, 402 a clock SCLK for data transfer anda selection signal SA and output permission signal whose contents changein synchronization with this clock.

(Merits of the present mode)

According to the third mode, in addition to similar merits to the secondmode described above, it is possible to reduce the number of elementscomprising the circuit. In other words, in the present mode, since thedetection signals output from each light-detecting element in the lightsensor panel 5 are time-division multiplexed before passing through theamplifier and filter, only one amplifying circuit and one filter need tobe provided.

INDUSTRIAL APPLICABILITY

According to the inventions described in claim 1 to claim 11, since thescanning cycle is detected by sensors located directly on an imagedisplay surface, and coordinate values are counted on this basis, it ispossible to detect coordinates accurately without distinguishing betweendifferent image display formats. Namely, accurate coordinates can beobtained regardless of whether the image display format is a standardtelevision format or an HDTV format, or whether the scanning methodinvolves interlaced scanning or sequential scanning. Moreover, if thepresent invention is applied in a television device capable ofdisplaying subframes, then since the relative coordinates within thesubframe can be detected, a game can be played in the subframe, forexample.

In particular, according to the invention described in claim 4, sincethe light-detecting means detect light emitted from the image displaysurface, then if this light-detecting means is positioned on the lightray gun in the game device, the position at which the player "shoots"can be obtained in the form of coordinates.

According to the inventions in claim 6 and claim 9, the beamed light isconverted directly into coordinates, which are therefore accuratecoordinates. The light-detecting means outputs the transmitted light asa direct detection signal, and the coordinates identifying meansconverts the position at which the light is beamed to coordinate values.

Furthermore, according to the inventions described in claim 8 and claim9, even if light having particular frequency components is admixed asexternal noise, since these frequency components can be removed byfilters, accurate coordinates detection is possible.

According to the inventions described in claim 5 or claim 10, it ispossible to provide a game device whereby it can be determinedaccurately whether or not a shot is successful.

We claim:
 1. A coordinates detecting device characterized in that itcomprises:a plurality of sensors located at prescribed positions in acoordinates detecting region for detecting coordinates set on an imagedisplay surface (4) which displays images by means of scanning lines;counters for counting the number of clock inputs with respect to thehorizontal direction of said image display surface and counting thenumber of scans in the vertical direction, based on the scan timing ofsaid scanning lines detected by said sensors; and a coordinatesdetermining circuit which, when a desired trigger signal is input froman external source, outputs the count values of said counters at thetime that this trigger signal is input in the form of relativecoordinates on said image display surface.
 2. A coordinates detectingdevice characterized in that it comprises:an initial position detectingsensor for detecting the scan timing of scanning lines, which is locatedat the initial scanning position in a coordinates detecting region fordetecting coordinates set on an image display surface which displaysimages by means of said scanning lines; a horizontal direction counterfor counting the number of inputs of a prescribed clock; a scanningcycle determining circuit for initiating a counting operation of saidhorizontal direction counter when a scan timing of said scanning linesis initially detected by said initial position detecting sensor, andsetting the value counted by said horizontal direction counter until thescan timing of the next of said scanning lines is detected by the saidinitial position detecting sensor as the scanning cycle count value; areset circuit for resetting the count value of said horizontal directioncounter each time said count value reaches said scanning cycle countvalue; and a horizontal coordinate determining circuit which, when adesired trigger signal is input from an external source, takes the countvalue of said horizontal direction counter at the time that this triggersignal is input and sets it as a relative coordinate in the horizontaldirection from said initial scanning position on said image displaysurface.
 3. In a coordinates detecting device according to claim 2, acoordinates detecting device characterized in that it comprises a finalposition detecting sensor for detecting the scan timing of said scanninglines, which is located at a desired final scanning position on saidimage display surface; a vertical direction counter for counting thenumber of times that the count value of said horizontal directioncounter reaches said scanning cycle count value; a horizontal limitdetermining circuit for setting the count value of said horizontaldirection counter when a scan timing of said scanning lines is detectedby said final position detecting sensor as a horizontal limit value; avertical limit determining circuit for setting the count value of saidvertical direction counter when a scan timing of said scanning lines isdetected by the final position detecting sensor as a horizontal limitvalue; and a vertical coordinate determining circuit which, when adesired trigger signal is input from an external source, takes the countvalue of said vertical direction counter at the time that this triggersignal is input and sets it as a relative coordinate in the verticaldirection from said initial scanning position on said image displaysurface (4).
 4. In a coordinates detecting device according to any ofclaims 1 to 3, a coordinates detecting device characterized in that itcomprises light-detecting means for receiving light emitted from adesired position (PO) on said image display surface, detecting the scantiming of said scanning lines, and outputting a detection signalrelating to the detected scan timing in the form of a trigger signal. 5.In a game device comprising a coordinates detecting device according toclaim 4, a game device characterized in that said light-detecting meansare provided in a shooting device for shooting at targets in a gameprogram represented on said image display surface.
 6. A coordinatesdetecting device characterized in that it comprises:light-detectingmeans for detecting light beamed from an external source onto a desiredposition on an image display surface for displaying images by means ofscanning lines, and outputting detection signals corresponding to thisbeamed light, which is transparent to light and is positioned such thatit covers said image display surface; and coordinates identifying meansfor detecting the position at which said light is beamed onto saidlight-detecting means on the basis of the detection signals supplied bysaid light-detecting means, and outputting the detected position asrelative coordinates on said image display surface.
 7. In a coordinatesdetecting device according to claim 6, a coordinates detecting devicecharacterized in that said light-detecting means compriseslight-detecting elements for detecting light beamed onto divisions of aprescribed size, arranged in the shape of a matrix; and said coordinatesidentifying means comprises: a horizontal coordinate identifying sectionfor identifying the column containing the light-detecting element wheresaid beamed light is detected, from a plurality of columns eachconstituted by a collection of said light-detecting elements alignedextending in the vertical direction of said image display surface; and avertical coordinate identifying section for identifying the rowcontaining the light-detecting element where said beamed light isdetected, from a plurality of rows each constituted by a collection ofsaid light-detecting elements aligned extending in the horizontaldirection of said image display surface.
 8. In a coordinates detectingdevice according to claim 6, a coordinates detecting devicecharacterized in that said coordinates identifying means comprises afilter for removing frequency components corresponding to the displaycycle of said images from the detection signals supplied by saidlight-detecting means.
 9. In a coordinates detecting device according toclaim 6, a coordinates detecting device characterized in that saidcoordinates identifying means comprises a filter for removing commercialpower supply frequency components from the detection signals supplied bysaid light-detecting means.
 10. In a game device comprising acoordinates detecting device according to claim 6, a game devicecharacterized in that it comprises a shooting device for emitting saidbeamed light when shooting at targets in a game program represented onthe image display surface.
 11. A coordinates detecting method comprisingthe steps of:arranging a plurality of sensors for detecting the scantiming of scanning lines in a coordinates detecting region for detectingcoordinates set on an image display surface for displaying images bymeans of said scanning lines; starting a horizontal direction count forcounting the number of inputs of a prescribed clock from the time thatsaid scanning lines are initially detected by one of said sensorslocated at an initial scanning position in said coordinates detectingregion; setting the value counted by said horizontal direction count upto the time that the next of said scanning lines is detected as thescanning cycle count value;resetting this count value and reinitiating acount in the horizontal direction each time said count value reachessaid scanning cycle count value, and simultaneously conducting a countin the vertical direction to count the number of times said count valuereaches said scanning cycle count value; setting the count valuesaccording to said count of clock inputs for the horizontal direction andsaid count for the vertical direction, respectively, as a horizontallimit value and a vertical limit value, when said scanning lines aredetected by one of said sensors located at a final scanning position insaid image detection region; andwhen a desired trigger signal is inputfrom an external source, outputting the count value according to saidcount in the horizontal direction and the count value according to saidcount in the vertical direction at the time that this trigger signal isinput as relative coordinate values on said image display surface.